Jeppesen Oral- Chapter 3 (Turbine Engine) Flashcards
With higher bypass, provides more thrust for same or even lower fuel consumption
Air inlet, compressor section, combustion section, turbine section, exhaust section, gearbox
Forward speed, compressor speed and density
Axial and centrifugal
Dove tail Fir-tree Bulb type
Two intra-rotating compressor sections
Can type, can-annular, annular, reverse-flow annular
Cooling air along inside of the liner
Flame propagation
They direct mass flow to drive the turbine rotor at a specific angle
By directing bleed air onto the face of the disc or by grooves cut in the disk
They are used as oil seals for the rotor shaft bearings
It is induction of the torque developed by a turboprop or turbo-shaft engine
Small power turbine, compressor and electrical starter
When it is supplying bleed air
With its own electrical starter and battery power
Typically the left main tank
At or near its rated speed. APU fuel control automatically adjusts the fuel flow to maintain rated speed
A load control valve modulates the pneumatic load to maintain the EGT within limits
First bleed air valve is closed, then it is run for a specific amount of time to allow EGT to stabilize. If suddenly shut down without cooling period, thermal shock and damage can occur
3 minutes
Fuel pressure
Overlapping of the mid-span shrouds of the fan blade
Any rubbing sound or unusual sounds from within the engine
What is the purpose of the stators in an axial-flow compressor?
The stators convert some velocity energy into pressure energy and change the direction of the air so it is proper for the next stage of rotors.
How many igniters are there normally in an aircraft turbine engine?
2
What is the main purpose of the turbine nozzle in an aircraft turbine engine?
The turbine nozzle directs the hot gasses as they leave the combustors so they will turn the turbine wheel with maximum efficiency.
What is meant by a free-turbine turboshaft engine?
A turbosaft engine that has a turbine wheel or stage of turbine wheels that is not used to drive the compressor of the gas generator section of the engine. This free turning drives the propeller in a turboprop engine or the transmission and rotor of a helicopter.
Why do some axial-flow turbine engines have more than one set of turbines and compressors?
A two-spool turbine engine has a low-pressure and a high-pressure compressor, each driven by its own turbine. The two independent systems operate at the speed at which they are most efficient.
What kind of bearings are used to support the rotor shaft of an aircraft turbine engine?
Antifriction bearings, such as ball bearings or roller bearings.
What is meant by a turbofan engine?
An axial-flow turbine engine in which the first-stage compressor blades are lengthened,so they can force air around the outside of the gas generator portion of the engine.
Why is it important that a turbojet engine be allowed to cool before it is shut down after it has been operated at a high power setting?
If the engine is shut down while it is hot, there is a possibility that the shroud will contract around the turbine wheel and seize the rotor.
What is meant by a hung start in a turbine engine?
A start in which ignition occurs, but the engine does not accelerate to a self-sustaining speed.
